A Palmerston North driver whose insecure load of steel pipes spilled off his truck killing an elderly Urenui couple was not the only one responsible, the High Court in New Plymouth has heard.

Henry Anthony Tawhai, 55, was yesterday sentenced to community work after pleading guilty to committing criminal nuisance on May 28, 2012, at Motunui on State Highway 3 after failing to properly secure the 25-tonne load of pipes.

In sentencing, Justice Toogood said Tawhai had 25 years of experience in heavy transport work but on the day he picked up the pipes from Bell Block he received no training or instruction from his employer or anyone else as to the safety measures needed with the unusual load and configuration.

And it was a serious error of judgment by Pipes New Zealand staff, who shared legal and practical responsibility with Tawhai for ensuring the load was secure, that they did not insist greater restraints were applied.

Yet Tawhai was the only person prosecuted, the judge noted.

Experts said the New Zealand truck loading code was difficult both to understand and to implement, and experts recommended the code was updated, the judge said. These issues were likely to be addressed at the inquest into the Suttons' deaths along with identifying any other person responsible for the insecure load.

The judge said he had to be mindful the charge carried a maximum penalty of one year's prison.

Earlier charges of dangerous driving causing death, drugged driving with cannabis in his blood, and manslaughter were dropped.

"Although there is no doubt that your failure to ensure that your load was secure led to these tragic deaths, you are not charged with an offence which holds you directly responsible," the judge said.

However, Tawhai's guilty plea reflected his acceptance of responsibility, at least in part, for the failure to secure the load.

Experts deemed the method of loading the smaller pipes into the larger pipes was "unusual and inappropriate".

The judge noted that Tawhai had for 25 years driven on the roads for many hours without committing any driving offence "and you are entitled to credit for that". The judge rejected the cannabis in the driver's blood as an aggravating factor but criticised the action.

The level of the active ingredient, THC, was consistent with him smoking the equivalent of a single cannabis cigarette within four hours of the blood sample being taken.

"It needs to be said that it was highly irresponsible and unacceptable for a heavy transport operator to consume cannabis before working," the judge said.

But the evidence fell short of making a connection between his use of cannabis and the manner of driving.

"That is why the earlier drug-related driving charge was withdrawn by the prosecution."

Prior to sentencing, the couple's elder son and daughter-in-law Warren and Pauline Sutton read out heart-wrenching victim impact statements to the court.

Several more were handed to the judge.

Both outlined their disgust at the lack of action by Tawhai in not properly securing his load on the day.

Sutton said the family had been devastated to the point it was left almost destroyed with their loss and distress that they had no chance to say goodbye.

He described the far-reaching turmoil and depression he had been trying to deal with "all because of your carelessness and incompetence". This was made worse because of Tawhai's lack of contact with them, lack of remorse and refusal to say sorry.

He did not accept this was due to the legal process, Sutton said.

"My parents are dead and you are very much alive."

Hopefully Tawhai had learned from his "massive mistakes", Sutton said.

Tawhai was sentenced to 225 hours of community work after a full 25 per cent reduction for his guilty plea.

He was not disqualified from driving because his heavy transport licence was suspended from the time of the accident.